1. Field of the Invention
The instant invention relates to an improved device for effecting a seal between a stationary guide vane structure and a rotor blade wheel.
2. Brief Description of the Prior Art
French Pat. No. 1,331,030 discloses a compressor vane ring wherein the individual vanes are fastened to inner and outer rings. The outer ring is formed by a plurality of arcuate segments having overlapping ends which are welded together. The overlapping portions serve as reinforcing ribs to increase the strength of the guide vane structure.
French Pat. No. 1,519,898 describes a rotor blade system wherein an outer ring connecting the blades is formed from a plurality of segments, each segment having generally "Z" shaped end portions. The end portions of one segment contact end portions of an adjacent segment at a mid-portion, while the portions on either side define a gap therebetween. The untwisting of the blades during their operation is utilized to provide a continuous connection between the blade segments on the rotor wheel.
French Pat. No. 2,514,409 discloses a rotor blade system wherein the blade wheel is formed from a plurality of segments. The inner, base portion of the segment is attached to a rotor disc, while the outer portion of the segment, which interconnects the tips of the blades, are interconnected by sealing means to prevent fluid leakage past the joint between adjacent segments. The sealing is affected by plate members inserted in correspondingly aligned slots in the ends of each segment.
The main object of the prior art in using the "Z" shape at the ends of the segments is to achieve a rigid and continuous connection between adjacent blades or blade segments when these are subjected to centrifugal action. Little, if any, consideration has been given to reducing the leakage of the gas passing across the turbine blades in a radial direction at the juncture of these segments, when the "Z" configuration is utilized.